Expansion joint



Nov, .29, 1932v R. R. RQEERTSCJN EXPANSION JOINT Filed Jan. 5, 1951 fill Hum

Patented Nov. 29, 1932 UNITED STA TES PATENT vOFI-"lcs ROBERT n. ROBitrsON, 'or cHieAGO, ILLINOIS EXPASION JOINT Application med January 5, A1931. 'serial No. 506,510.

cap to facilitate forming a groove in the body Vof the road lfor the reception of asphaltum or the'like above the inner cap after removal of the mould cap from the web.

It is an object of this invention to provide anexpansion joint wherein a base is provided with a hollow spring web having 'a springl cap engaged therein beneath a re- Y movable mould cap to support an expansion joint filling thereon .after concrete has been poured and themould cap has been removed.

It is also an objectof this invention to provide an expansion joint adapted to be. K staked in position on a road sub-gradeand having the supporting sectionthereof coated with grease or a similar material'to facilif.

- tate slidable movements ofthe concrete road sections thereover when contraction or eX- pansion takesplace. l. 'j A,

It is a further object of this invention to provide `a concrete road expansion joint wherein a hollow flexible webv having inner and outer caps supported therein to enclose retaining stakes which project through the hollow web and through an arched base the upper surfaces of which are coated withv a lubricant which serves to prevent adherence of the concrete to the base to allow for move- 40 ment ofthe concrete' sections overthe base resulting from the expansion or contraction of the concrete due to temperature changes.

It is an important object' of this invention Y to provide a concrete road expansion ointof simplified and inexpensive construction provided with a greased base and a web consisting of vflexible spaced wallsto permit retaining stakes to project therebetween and through an arched flexible inner cap supf ported-by the web beneath a" removable mould cap, which after concrete has been poured and allowed to partially set is removed to permit a filling of expansible m'aterial to be deposited in the groove and supported upon the inner cap sothat the filling, is maintained in position when the Webforming walls are moved toward Or away from one another due to temperature changes.

Other and `further important objects will be apparent from the disclosures in the accompanying drawing and the specification.

The invention` (in a preferred form) is i1- lustrated in the drawing and hereinafter more fully described. j

On the drawing: f

Figure l is a fragmentary vertical section through a concrete road having embedded therein an improved expansion joint embodying thevprinciples ofthis invention, and illustrating a filling of expansible material above the inner cap replacing the removed mould cap.

Figure 2 is an enlarged fragmentary vertical vsection of the expansion joint embedded `in concrete with the removable'mould cap still in position. Y ,j

F'gure is a fragmentary detail section taken on line III-III of Figure2.` Y

Figure 4 is a transverse vertical section of a modified form of expansion joint.

Figure 5 is an enlarged fragmentaryhori- Zontal detail view taken von line IV.IV-of VFigure 4 with the mould cap omitted.`

As lshownon the drawing: j The reference numeral l indicates a concrete road sub-grade having'supported thereon an expansion joint comprising a comparatively heavy metal base 2, having Vthe longitudinal margin thereof bent downwardly to 'afford roundedflanges 3 producing an arched base which, when in use, is adapted to 4be pressed down into the sub-grade with the top surface of the base plate 2 substantially flush with the top surface of the road sub-grade.

Applied to the upper surface of the base i is a coating of grease 4 or any other suitable slippery substance which will serve to prevent the adherence of concrete to the base to permit the concrete sections '5 forming the upper portion of theroad, to slidably move overthe' base when said sections are moved by the contraction or expansion of the concrete resulting from temperature changes.

Secured longitudinally, by means of rivets 6 or other suitable means upon the top of the base plate 2 is a web constructed of comparatively thin light weight sheet metal in the form of a U-sliaped body comprising a base 7 which connects a pair of upright flexible walls or plates 8. The web is thus of hollow construction having the upper margins of the side walls 8 bent outwardly and upwardly to form a channel head 9.

Sprung into seated engagement with the channel head 9 is an inner arched cap 10 which lits against the side lianges of the head 9 and serves as a cover to closel the chamber formed between the web walls 8.

The inner cap 10, the bottom plate 7 of the web and the base plate 2 are all provided with apertures or openings for the reception of retaining stakes or pins 11 which are inserted to project downwardly through the inner cap 10, through the web chamber and base 7 and through the openings in the base f complete.

With the expansion joint positioned upon the sub-grade 1 as described, concrete is poured upon the sub-grade to embed the expansion joint producing the road sections 5. The grease coating 4 applied to the top surface of the base plate 2 prevents the concrete from adhering to the base of the expansion joint. After the concrete has been tamped and leveled, it is permitted to set a required amount after which the mould cap 12 is re- Y moved leaving a channel or groove bounded by rounded side walls. The groove is iilled with asphaltuni or pitch which fillings is supported upon the arched inner cap 10 to torni an expansion strip 13.

Figures 4 and 5 illustrate a modiiied form of expansion joint comprising an arched Y metal base 14 provided with stake apertures of the base 14 are the lower flanges 16 of a pairor openings. The upper surface of the baseV 14 is covered with a coating of grease 15 or the like to prevent the adherence of concrete to said base and permitting the concrete sections in which the expansion joint is enibedded to have relative sliding engagement over the base 1 4 when the concrete sections are expanded or contracted due to temperature changes.

Riveted or otherwise secured upon the top of spaced web forming walls or plates 17.

The upper margins of the walls 17 are bent outwardly and upwardly to form an upper channel head 18. Sprung or frictionally seated in the channel head 18 is an apertured arched inner cap 19 which serves as a cover to close the upper end of the chamber formed between the web side walls 17.

Projecting through the openings 20 in the inner cap 19 and downwardly between the web walls 17 are retaining stakes or pins 21, which project through openings in the base 14 and are driven into the road sub-grade to hold the expansion joint staked in position. The inner cap 19 and the upper ends of the stakes 21 are enclosed by means oie a removable mould cap 22 which is left in position until after the concrete is poured and has set. The mould cap is then removed to leave an expansion groove in the concrete which is thenv filled with a filling of asphaltum or pith toY form an expansion strip 13 which rests upon the inner cap which is permitted to expand and contract as the web walls 17 are moved away or toward one another due to contraction or expansion of the concrete sections be-C tween which the expansion joint is positioned.

It will be noted that an expansion joint has been devised having a sufiiciently heavy greased base supporting a hollow, light metalv web for supporting an arched flexible inner@ cap. The retaining stakes are enclosed loetween the web walls, thereby aiording an arrangement permitting the web walls to be moved toward or away from one another al' lowing the inner cap to be compressed or eX-' panded to keep the top of the web chamber closed when expansion or contraction of the concrete sections occurs due to temperature changes. l

When mounted in position, the base of they expansion joint is sunk or pressed into the sub-grade permitting the greased surface of the base to be so positioned that a sliding movement of the concrete sections adj acont the sides of the web may readily take place over said base when temperature changes cause expansion or contraction of the concrete.

It will, of course, be understood that vari-y ous details of construction may be varied through a wide range without departingr from the principles of this invention, and it is therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. An expansion joint comprising an apertured base, a hollow web secured thereon, a channel formed on said hollow web, an aper tured arched cap seated in said channel, staking members projecting through said apertured arched cap, said hollow web and through saidl base to secure the expansion joint in position, and a removable mould cap supported by said channel to enclose said cap.

2. An expansion joint comprising an arched base, a hollow web supported thereon, an inner cap seated in said hollow web,

Y and an outer mould cap removably supported over said inner cap.

3 An expansion joint comprising an arched base, a hollow web supported thereon, an expansible and contractible inner cap seated in said hollow web, staking members projecting through said inner cap, said hollow web and said base, and a mould cap removably engaged on said hollow web to enclose the inner cap, and the upper ends of said staking members.

4. An expansion joint comprising a base, a webthereon, means for staking the expansion joint in position, and inner and outer caps supported on said'web.

5. An expansion joint comprising a base, a web secured thereon, a coating of grease on said base, an expansible and contractible inner cap seated in said web, staking members projecting through said inner cap, said web and said base to hold the expansion joint secured in position, and an outer cap removably engaged on said web to enclose the inner cap.

6. An expansion j oint'comprising an apertured flanged base, a hollow web secured 1ongitudinally thereon, a channel formed on the upper end of said web, an arched apertured' Vinner cap seated in said channel, kstaking members projecting through said inner cap, said hollow web and through said apertured base, an outer Vmould cap engaged with said channel to enclose the inner cap, said flanged base having a coating of grease thereon to facilitate movement of concrete sections thereover when the expansion joint is embedded in a concrete structure.

7 An expansion joint comprising-a pair of spaced walls, a support therefore, and an. arched spring closure sprung between said walls to form a iexible support for an eX- pansible material, said iexible support adapted to be adjusted to variable widths depending upon Variations in the spacing of said walls.

8. An expansion joint comprising a pair of spaced resilient walls, means between said walls for supporting the same in position, and an eXpansible and contractible spring closure supported by said walls for supporting an eXpansible material above the eXpansion joint.

In testimony whereof Irhave'hereunto subscribed my name at Chicago, Cook County,

Illinois. Y Y

ROBERT R. ROBERTSON. 

